Sitting in the back of a red flatbed Ford pickup, Tennessee congressional candidate Roy Herron (D) says "This old truck has about 400,000 miles on it."

Doing his best Scott Brown impression, (although Herron's pickup is a bit older) he is using the truck as a proxy for his fiscal conservatism as Herron works to define himself as a middle-of-the-road Democrat in the race for retiring Rep. John Tanner's (D-Tenn.) seat. 

"In my family, we get a new truck every 22 years whether we need one or not," Herron says. "Grandaddy got one in '54, daddy in '76, '98 was my year."

A Tennessee state senator, Herron is awaiting a general election opponent as his Republican challengers are locked in a nasty primary. 

The leading candidates on the GOP side are farmer Stephen Fincher, Shelby County Commissioner George Flinn and physician Ron Kirkland. The three have been in attack mode for weeks, each trying to stake out the more conservative ground in the primary race. 

Fincher was an early recruit of the NRCC and is in the top level of the committee's Young Guns program. The primary is August 5. 

Republicans fully expect Fincher will emerge battle-tested and make the race highly competitive should he win the primary, but he's had to endure millions of dollars in attacks and spend considerably from his own coffers for the GOP primary.

In the folksy Web video, Herron also offers some money-saving tips, noting the manual transmission, if driven properly, can stretch a gallon of gas by another mile or two.

"If this country knew how to get by with 400,000 mile trucks, those folks up in Washington wouldn't be spending us into oblivion and piling up debt on our kids and our grandkids."

Herron looks to be the beneficiary of the GOP primary fight so far, using the time stockpile some cash and tout his 2nd Amendment credentials to voters.